The inventive concept relates to range finding and/or range imaging and more particularly, to depth sensors of range finders and/or range imaging cameras such as time-of-flight (TOF) cameras. The inventive concept also relates to microlenses and to a method of fabricating the same.
Range finding is a technique of measuring the distance to a target without using physical means to do so, and range imaging is a technique used to produce an image of a scene. Typical range imaging cameras, for example, include an illumination system for illuminating a subject, such as a person, and depth pixels for collecting light reflected from the subject and producing data representative of an image of the subject. A time-of-flight camera (TOF camera) is a range imaging system that has the ability to produce a 3-D image of a scene. To this end, the depth sensor of a TOF camera may include a light source for illuminating the subject (the scene), and depth pixels which receive light reflected from the subject and generate photons in response to incident light. The photons are sensed to provide information on the distance between the camera and the subject. That is, the generation of the photons allows the time of flight of the light to be measured, and the distance between the subject and the camera can be calculated based on the time of flight and the known speed of light. Thus, the performance of a depth sensor is crucial to the precise calculation of the distance between the camera and the subject and/or is crucial to the quality of the image of the subject that can be produced.